Safety Monitoring of COVID Vaccines and Perception of Post-vaccination Side-Effects: Preliminary Findings From The First Month of Routine Monitoring in a Hospital Vaccination Setting of China (preprint)

Objectives: This study aims to explore the occurrence of post-vaccination side-effects from COVID-19 vaccines and its affecting factors in a hospital vaccination setting of China.Results: A total of 811 vaccinees aged 17 to 58 years, who finished the full package of two doses in February 2021, have been recruited at the second vaccination uptake. Among all, there have been 66 participants who reported one or more mild side effects, while none of them developed severe cases. Those with history of immune deficiency were more likely to report side effect(s). Although with several concerns, most participants showed willingness to get vaccinated (98.8%) with relevant high proportions of perceived safety (99.5%) and effectiveness (97.3%).

Portable Magnetic Particle Spectrometer (MPS) for Future Rapid and Wash-free Bioassays (preprint)

Nowadays, there is an increasing demand for more accessible routine diagnostics for patients with respect to high accuracy, ease of use, and low cost. However, the quantitative and high accuracy bioassays in large hospitals and laboratories usually require trained technicians and equipment that is both bulky and expensive. In addition, the multi-step bioassays and long turnaround time could severely affect the disease surveillance and control especially in pandemics such as influenza and COVID-19. In view of this, a portable, quantitative bioassay device will be valuable in regions with scarce medical resources and help relieve burden on local healthcare systems. Herein, we introduce the MagiCoil diagnostic device, an inexpensive, portable, quantitative and rapid bioassay platform based on magnetic particle spectrometer (MPS) technique. MPS detects the dynamic magnetic responses of magnetic nanoparticles (MNPs) and uses the harmonics from oscillating MNPs as metrics for sensitive and quantitative bioassays. This device does not require trained technicians to operate and employs a fully automatic, one-step, wash-free assay with user friendly smartphone interface. Using a streptavidin-biotin binding system as a model, we show that the detection limit of the current portable device for streptavidin is 64 nM (equal to 5.12 pmole). In addition, this MPS technique is very versatile and allows for the detection of different diseases just by changing the surface modifications on MNPs.